Machine for blending tobacco or the like

ABSTRACT

Two or more types of tobacco are fed by separate conveyor lines into a blending unit wherein such types are mixed. One of the conveyor lines contains a measuring and control unit which measures the rate of tobacco feed and controls the rate of operation of each other conveyor line so that the ratio of tobacco types reaching the blending unit remains within a desired range. The measuring unit can also control the operating rate of one conveyor line.

United States Patent Waldemar Wochnovvskl Hamburg-Volksdori; HelmutBsumnnn, Hamburg-Bergedorl,

[72] Inventors both of. Germany [21 Appl. No. 635,597

I22] Filed May 2, 1967 [45] Patented July 6, 1971 73] Assigncellauni-Werke Korber 8: Co. KG.

Hamburg-Bergedori, Germany I32] Priority May 4, 1966 [33] Germany I54]MACHINE FOR BLENDING TOBACCO OR THE 2,656,142 10/1953 Wcckerly 177/702,827,058 3/1958 Bogarty 131/108 3,098,572 7/1963 Ouestcr H 131/21 X3,204,71 l 9/1965 Boadlc et a1. 177/70 3,209,845 10/1965 Hollander...177/70 3,232,296 2/1966 Dreher 131/22 (A) 3,242,321 3/1966 Chopc...131/21 X 3,113,576 12/1963 Bell 131/21 (1)) 3,146,780 9/1964Harrison,.1r. ct 31.. 131/21 (13) 3,428,052 2/1969 Patterson 131/21 (B)X FOREIGN PATENTS 495,614 4/1930 Germany 131/149 673,308 3/1939Germany.. 131/149 1,022,141 l/l958 Germany... 131/149 1,103,209 3/1961Germany 131/149 730,527 5/1955 Great Britain 131/136 82,123 10/1956Netherlands 131/149 826,914 l/1938 France 131/109 83,123 10/1956Netherlands Primary Examiner-Joseph S. Reich Attorney-Michael S. StrikerABSTRACT: Two or more types of tobacco are fed by separate conveyorlines into a blending unit wherein such types are mixed. One of theconveyor lines contains a measuring and control unit which measures therate of tobacco feed and controis the rate of operation of each otherconveyor line so that the ratio of tobacco types reaching the blendingunit remains within a desired range. The measuring unit can also controlthe operating rate of one conveyor line.

PATENTEU JUL 619?! SHUKI 1 0F 6 INVENTORS 1J0 BY wmsgmw, W

PATENTED JUL 5197:

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PATENTEU JUL 6 law SHEET t [If 6 IN VEN TORS:

PATENTED JUL 6 Ian 590 a M SHEET 5 0F 6 18 1 9 ms 9/ E d 135s 1360 F I21351 135a 11s4 IN VE NTOPS PATENTEU JUL 6 l9?! SHEU 8 OF 6 I! J I I INVENTORS MACHINE FOR BLENDING TOBACCO OR THE LIKE CROSS-REFERENCE TORELATED APPLICATION Certain devices and circuits which can be utilizedin the blending machine of the present invention are disclosed in US.Pat; No. 3,4l9,Ul granted Dec. 3i, l968 to Waldemar Wochnowski andassigned to the same assignce.

BACKGROUND OF THE INVENTION The present invention relates to blending offibrous matern als, particularly to blending of tobaccos. Still moreparticularly, the invention relates to improvements in machines whichcan be utilized for blending different classes, types. qualities, gradesor vintages of tobacco.

Blending is one of the most complex and important procedures in themanufacture of cigarettes, cigars and other tobacco products. This isdue to the fact that all advantageous characteristics which a smoker,sniffer or chcwer ettpccts from his or her preferred brand cannot beobtained by utilizing a single type, class, grade or quality of leaf.For example, one type of leaf may be highly aromatic but does not burnwell, and another type oflcaf may be too strong or too weak. Manu'facturers of tobacco products have developed recipes for blendingdifferent tobacco types in such a way that a blend nonnally containsleaf from 2 or more yeals' crops and that such blend contains a mixtureof Oriental with Burlcy, Vir' ginia, Maryland, flue cured and/or others.

Serious problems arise when the blending of different tobacco types iscarried out on a large scale with automatic machinery. As a rule,different tobacco types are treated separately prior to blending, andthe resulting mixture or blend then undergoes one or more additionaltreatments. This is due to the fact that different tobacco types must betreated in different apparatus and also because a specific treatmentwhich is needed for one tobacco type might not be needed at all foranother tobacco type. For example, treatment of Oriental tobaccosfollowing moistening of bales is very simple and consumes little time.On the other hand, preliminary treatmom of Burley (prior to blending) ismuch more extensive and consumes more time.

Accordingly, it is an important object of our invention to provide anovel and improved automatic machine which can blend two or more tobaccotypes in such a way that the ratio of tobaccos in the blend varies verylittle or not at all.

Another object of the invention is to provide a machine which can blendtobacco: and maintains a desired ratio between various tobacco typesregardless of differences in time required for preliminary treatment ofindividual tobacco types.

A further object of the invention is to provide a machine which canblend two or more tobacco types by maintaining the desired ratioregardless of anticipated or unforeseen fluctuations in the rate ofdelivery of such tobacco types.

A concomitant object of the invention is to provide a machine which canbe reset to form different blends and which can be converted fromblending of two tobacco types to blending of three or more tobaccotypes, or vice versa.

Another object of the invention is to provide a machine which canautomatically terminate the blending of two or more tobacco types whenthe resulting blend contains a predetermined amount of a given tobaccotype.

A further object of the invention is to provide a blending machine whoseoperation is independent of the number of treatments to which thetobacco types must or should be su bjccted prior to blending.

SUMMARY OF THE INVENTION One feature ofthe present in ention resides inthe provision of a machine for blending various types of tobacco or likefibrous materials. The machine comprises blending means which mayinclude one or more rotary drums installed upstream of one or moreprocessing apparatus wherein the blend undergoes further treatment, atleast two conveyor lines for supplying to the blending means differenttypes of material (for example, shredded tobacco and comminuted tobaccoribs.) measuring means which may include a weighing conveyor installedin one ofthe conveyor lines to measure the rate of material flow to theblending means, and proportioning means provided in other conveyor linefor regulating the rate of material flow as a function of the results ofmeasurements carried out by the measuring means.

The proportioning means may include a feeder belt which can be driven atseveral speeds, and a regulator or speed changer assembly which receivessignals from the measuring means to change the speed of the feeder beltin response to changes in the rate of material feed in the one conveyorline.

The novel features which are considered as characteristic of theinvention are set forth in particular in the appended claims. Theimproved blending machine itself, however, both as to its constructionand its mode of operation, together with additional features andadvantages thereof, will be best understood upon perusal of thefollowing detailed description of certain specific embodiments withreference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a flow sheet illustrating indiagrammatic form certain elements of a machine which may be utilizedfor.auto matic blending oftwo tobacco types;

FIG. 2 is a similar flow sheet illustrating certain elements of amachine which is intended for blending of three tobacco yp FIG. 3 is aflow sheet illustrating a blending machine which constitutes amodification ofthe machine shown in FIG. 2;

FIG. 4 is a flow sheet illustrating a blending machine which constitutesa modification of the machine shown in FIG. 2 or FIG. 5 is a fragmentarytop plan view ofa blending machine which is similar to the machinerepresented by the flow sheet of FIG. I;

FIG. 6 is a fragmentary top plan view ofa blending machine whichconstitutes a first modification of the machine shown in HO. 5;

FIG. 7 is a fragmentary top plan view ofa blending machine whichconstitutes a second modification ofthe machine shown in FIG. 5;

FIG. 8 is a fragmentary schematic side elcvational view of a furtherblending machine;

FIG. 9 is a fragmentary schematic view of a blending machine forblending two types of tobacco, Virginia and Oriental, for example;

FIG. I0 is a diagrammatic schematic view of a first modifi' cation ofthe blending machine shown in FIG. 9;

FIG. I] is a diagrammatic schematic view of a second modification of theblending machine shown in FIG. 9;

FIG. I2 is a diagrammatic schematic view of a third modification of theblending machine shown in FIG. 9;

FIG. I3 is a top plan view of a timelag unit which can be utilized inthe blending machines of FIGS. I to 4; and

FIG. I4 is a vertical section substantially as seen in the direction ofarrows from the line XIV-XIV of FIG. I3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. I is a flow sheetillustrating in diagrammatic form a machine for blending two tobaccotypes, grades, classes or qualities. The numerals 200] and 2002 denotetwo conveyor lines each of which advances one of the two tobacco types.The lines 200] and 2002 deliver tobacco to a blending means or blendingunit 2004 (c.g., a rotary drum) which occupies a blending location, andthe resulting blend is advanced by a common conveyor line 2003. Thefirst tobacco type which is advanced in the path defined by the conveyorline 200] is treated during passage through a pair of serially arrangedprocessing apparatus 2006 and 2007, and the second tobacco type which isadvanced in the path defined by the conveyor line 2002 is treated duringpassage through processing apparatus 2008 and 2009. A further processingapparatus 2005 treats blended tobacco which is advanced in the pathdefined by the common conveyor line 2003. Depending on the nature of thefirst and second tobacco types, the processing apparatus 2005 to 2009may include moistening, casing-applying, cooling, drying, cutting,heating, dcstalking, mixing, bulking and other devices. A proportioningor metering unit l0 is in stalled in the conveyor line 200l downstreamof the processing apparatus 2006, 2007, i.c., this proportioning unit20l0 is the last unit through which the first tobacco type passes on itsway to the blending location which accommodates the blending unit 2004.The proportioning unit 2(ll0 comprises an automatic fccdcr 201 l whichhas storage capaci ty, a weighing or measuring conveyor 20I2 whichdetermines the rate of tobacco flow toward the blending unit 2004, and aregulator or speed changer 2013 which controls the operation of theassociated automatic feeder 20". The weighing conveyor 2012 supplies tothe regulator 2013 impulses which indicate the actual rate of tobaccoflow and the regulator 20l3 changes the delivery of the feeder 201 Iwhen such actual rate deviates from a predetermined or desired rate. Thefeeder 20 is capable of storing a variable quantity of tobacco andinsures that the rate at which the weighing conveyor 20l2 receivestobacco is a function of the difference between the desired and actualrates.

The second conveyor line 2002 accommodates a weighing or measuringconveyor 20l4 which is located downstream of the processing apparatus2008, 2009. The weighing conveyor 2014 supplies to the regulator 20l3impulses which indicate the aforementioned predetermined or desired rateof tobacco flow through the weighing conveyor 20 [2 in the conveyor line2001. The conveyor, lines 200i, 2002 further accommodate two delay ortimelag units 2015, 2016 which are set in such a way that the timerequired by successive increments of the first tobacco type to cover thedistance between the proportioning unit 2010 and the blending unit 2004is the same as the time required by successive increments of the secondtobacco type to cover the distance between the weighing conveyor 20" andthe blending unit 2004. This insures that, despite the fact that therate of tobacco throughput in the conveyor lines 2001, 2002 upstream ofthe feeder 20]] and weighing conveyor 20l4 might fluctuate for reasonswhich cannot be foreseen (for example, due to the characteristics ofprocessing apparatus 2006 to 2009), the ratio of the two tobacco typesin the blending unit 2004 remains unchanged. A delay or timclag unitwhich can be used in the blending machine of FIG. I is shown in FIGS. 13and [4.

The rate at which the feeder 200i supplies tobacco to the weighingconveyor 20l2 depends on the rate of tobacco advance through theweighing conveyor 2014. ln other words, the rate of tobacco flow in thepath defined by the conveyor line 2002 controls the rate of tobacco flowin the path defined by the conveyor line 200]. The weighing conveyor2014 controls the proportioning unit 20l0 which latter, in turn,controls the amounts of the first tobacco type downstream of the lastprocessing apparatus in the conveyor line 2001. Thus, any unforeseenfluctuations in the rate of feed of the first tobacco type can becompensated for ahead of the blending unit 2004, especially since thefeeder 20]] can store tobacco to compen sate for eventual interruptionsin delivery from the processing apparatus 2006. The conveyor 20 is arated value setting means for the proportioning upit 20I0.

FIG. 2 is a flow sheet illus'trating in diagrammatic form a machine forblending three tobacco types, for example, Burley, Oriental and Virginiatobacco. This machine comprises three conveyor lines 2020, 202i and 2022which deliver the respective tobacco types to a blending unit 2024installed in a common conveyor line 2023. The numerals 2025 to 203!denote processing apparatus the first of which is installed in thecommon line 2023 downstream of the blending unit 2024.

The apparatus 2026 and 2027, 2029 and 2030, 2028 and 2031 arerespectively installed in the conveyor lines 2020, 202] and 2022. Twoproportioning or metering units 2032 and 2033 are installed in the lines2020 and 2022, each thereof is analogous to the proportioning unit 20l0of FIG. I. Their automatic feeders, weighing or metering conveyors andregulators or speed changers are respectively denoted by the numerals2035 and 2036, 2037 and 2038, 2039 and 2040. The conveyor line 2021accommodates a weighing conveyor 2034 which is located upstream ofthcprocessing apparatus 2029, 2030 and sends signals to the regulators2039, 2040 in the same way as described in connection with the weighingconveyor 2014 and regulator or speed changer 2013 of FIG. I. The natureof processing apparatus 2029, 2030 in the conveyor line 202I is assumedto be such that these apparatus do not cause any unforeseen fluctuationsin the rate of delivery of the respective tobacco type. The apparatus2029 and 2030 are the sole processing apparatus for tobacco which isconveyed by the line 202l and it will be seen that the weighing conveyor2034 is located at the receiving end of this line 2021. For example, theline 202! can receive tobacco from hogsheads or bales Signalstransmitted by the weighing device 2034 will control the rate at whichthe blending unit 2024 receives tobacco from the conveyor lines 2020 and2022. The connections between the weighing conveyor 2034 and regulatorsor speed changers 2039, 2040 respectively accommodate adjustableauxiliary delay or timelag units 2043, 2044 which comprise travellingmagnetic tapes serving to record impulses furnished by the weighingconveyor 2034. Reference may be had to FIG. 3 in the US. Pat. No.3,419,0l5 of Wochnowski. The recordings are reproduced with a requisitedelay and the resulting signals are transmitted to the regulators orspeed changers 2039, 2040. In order to compensate for remainingdifferences in time required for travel of tobacco types to the blendingunit 2024, the lines 202i, 2022 respectively accommodate adjustabledelay or timelag units 2041, 2042 which are analogous to the delay units20l5, 20l6 of HG. I. The delay units 204I-2044 are set in such a waythat the ratio of three tobacco types reaching the blending unit 2024remains constant.

in the machine of FIG. 2, the rate at which the conveyor line 202]supplies tobacco to the blending unit 2024 controls the rate at whichthe blending unit receives tobacco from the conveyor lines 2020 and2022. Each of the feeders 2035, 2036 is preferably arranged toaccommodate a variable supply of the respective tobacco type.

The flow sheet of HO. 3 illustrates in diagrammatic form a thirdblending machine which comprises three conveyor lines 2050, 205] and2052 serving to feed three tobacco types to a common co'nvcyor line 2053accommodating a blending unit 2054. The numerals 2055 to 2062 denoteprocessing apparatus each of which can subject the respective tobaccotype to a different treatment. Of course, two or more processingapparatus can subject tobacco to the same form of treatment. Thismachine further comprises three proportioning or metering units 2063,2064, 2065 which are respectively installed in the lines 205], 2052 and2050. The construction of each of these proportioning units is the sameas that of the proportioning unit 20l0 in the machine of FIG. I. Theprocessing apparatus 2062 is installed in the conveyor line 205!downstream of the respective proportioning unit 2063. The other twoproportioning units 2064, 2065 are located downstream of the respectiveprocessing apparatus 2056, 2057 and 2059, 2060. The processing apparatus2062 operates in the same way as the apparatus 2029, 2030 of FIG. 2,i.e., it does not cause any unforeseen fluctuations in the rate at whichthe corresponding tobacco type is caused to pass therethrough and ontoward the blending location. This tip paratus 2062 serves to sendsignals to the regulator or speed changer 2066 of the proportioning unit2063 in the conveyor line 2051. The weighing conveyor 2067 of theproportioning unit 2063 is connected with the three regulators or speedchangers in the same way as described in connection with the weighingconveyor 2034 of FIG. 2. The lines 2050 and 2052 respectivelyaccommodate delay or timelag units 2068 and 2069.

The proportioning unit 2063 insures that the processing ap paratus 2062invariably receives a desired amount of tobacco per unit oftimc. ltsweighing conveyor 2067 controls the regulators of the proportioningunits 2064, 204 in conveyor lines 2052, 2050 to insure that the ratio ofthe three tobacco types remains at least substantially unchanged.

Referring now to FIG. 4, this illustration is a flow sheet of a fourthblending machine including three conveyor lines 2070, 207], 2072 whichdeliver three tobacco types to a common conveyor line 2073 accommodatinga blending means or blending unit 2074. The numerals 2075 to 2081 denoteprocessing apparatus in the lines 2070-2073. The apparatus 2075 to 2080are the sole processing means for the tobacco types which advance withthe conveyor lines 2070-2072. The lines 2070-2072 respectivelyaccommodate adjustable first proportioning or metering units 2082, 2083,2084 which are located upstream of the associated processing apparatus2075-2076, 2077-2078, 2079-2080 and second proportioning or meteringunits 2085, 2086, 2087 which are located downstream of the associatedprocessing apparatus. Each of the proportioning units 2082-2087 isanalogous to the proportioning unit l0 in FIG. I. The proportioningunits 2082-2084 are connected to each other in such a way that theweighing or measuring conveyor 2088 of the proportioning unit 2083 sendssignals to the three regulators or speed changers. Analogously, theweighing or measuring conveyor 2089 of the proportioning unit 2086 sendssignals to the regulators or speed changers of the units 2085-2087. Thelines 2070, 2072 respectively accommodate delay or timclag units 2090,209I which are located downstream of the proportioning units 2085, 2087and perform the same functions as the units 20I5, 20I6 of FIG. I. Thefirst three proportioning units 2082-2084 insure that the desired ratiobetween the three tobacco types is established, to a considerablyextent, at the time when such tobacco types enter the respectiveconveyor lines. The second proportioning units 2085-2087 serve tocompensate for unforeseen fluctuations in the rate of tobacco feed dueto peculiarities and/or malfunction of the processing apparatus2075-2080.

FIG. 5 illustrates in greater detail a blending machine with analogspeed changer circuitry which is adapted to provide the flow patterns,etc.. similar to that indicated in FIG. I. The first conveyor line 3includes endless belts I, IA. IB and 32, and the second conveyor line 4comprises endless belts 2, 2A 3| 3IA, 3IB. The common conveyor linecomprises an endless belt 34. A blending unit is shown at 33, and thesecond conveyor line 4 includes a proportioning unit 4| having aweighing conveyor 43 and an automatic fcedcr 42.

The belts l and 2 are respectively driven by variable-speed electricmotors S and 6. A regulator or speed changer for the motor 6 includes abridge circuit 7 wherein the taps I0, I I are constituted by the slidingcontacts or sliders of two potentiometers 8 and 9 connected in mirrorsymmetrical branches of the circuit 7. The sliders I0, I I are displacedsynchronously with the movement of belts I and 2. The distances coveredby these sliders are proportional to but shorter than the distancescovered by the upper stringers of the belts I and 2. The speed reducingtransmissions for the sliders I0, II are shown at In, lb and eachthereof receives motion from a roller or sprocket of the respectivebelt. The potentiometer 8 is connected in se' ries with a delay ortimelag unit l2 which can be adjusted manually by an adjuster I3. Twoother branches of the bridge circuit 7 respectively comprisesymmetrically arranged fixed resistors I4, IS. The connection to acurrent source includes terminals I6, I7. The sliding contact or sliderI9 ofa variable resistor I8 in the diagonal or zero branch of the bridgecircuit 7 is connected with the motor 6 for the belt 2, the r.p.m. ofthe motor 6 varies as a function of voltage changes, i.e., as a functionof changes in the setting of the slider I9. Thus, the bridge circuit 7insures that the motor 6 rotates at a speed which is in a predeterminedrelation to the speed of the motor 5 for the belt I. This relation isoffset in time due to the provision of delay or timelag unit 12 and isadjustable by changing the position of the slider I9.

The belts I and 2 respectively deliver tobacco to belts IA and 2A, andthe belts lA, 2A respectively deliver tobacco to belts I8, 31. Thedirections in which the belts of FIG. 5 advance the respective tobaccotypes are indicated by arrows. The belts IA, IE, 32, 2A, 3l, 3 l A, 318and 34 are driven by a common prime mover 35, c.g., an electric motor.This motor 35 also drives the blending unit 33; the latter may comprisea rotary drum which effects thorough intermixing of tobaccos coming fromthe belts 3"! and 32. in the illustrated embodiment, the two tobaccotypes merge on the belt 32 immediately upstream of the blending unit 33.

The conveyor line 3 accommodates a composite processing apparatus 30which includes three tobacco cutting machines 37. These machines 37receive stemmed tobacco (laminae) from the belt IB and deliver shreddedtobacco onto the upper stringer of the belt 32. Excess stemmed tobaccowhich cannot be processed by the cutting machines 37 is fed to arecirculating conveyor 36 which includes three endless belts 36a, 36b,366 the first of which receives stemmed tobacco from the belt 18downstream of the inlet to the last cutting machine 37. The belt 360returns such tobacco onto the belt lI-l upstream ofthe first cuttingmachine 37. The belts 3611-360 are driven by the motor 35. The belt 36!:is adjacent to a level-sensing devicc 38 which includes a maximum levelindicator and a minimum level indicator. This device 38 preferablycomprises two light sources and two photoelectric receivers similar tothose which will be described in connection with FIG. 8. Thelevel-sensing device 38 sends signals to a speed changer or regulator 39for the motor 5 of the belt I.

A weighing or metering conveyor 40 is associated with the belt 32 of thefirst conveyor line 3 to determine the rate of tobacco delivery by thebelt 32 and to send signals to a speed changer or regulator 53 for motor35. The weighing conveyor 40 is a functional equivalent ofthe weighingconveyor 20I4 in FIG. I and is located upstream of the point where thebelt 313 discharges the second tobacco type onto the belt 32. The belt32 cooperates with the weighing conveyor 40 to activate the same and thespeed changer 53 regulates the speed of the belt 32 through its powersource, the motor 35.

The belt I, motor 5, recirculating conveyor 36, speed changer 39 andlevel-sensing device 38 together constitute a first proportioning unit29 for tobacco which is being fed by the conveyor line 3. Therecirculating conveyor 36 constitutes a feeder of the proportioning unit29 and is arranged to accumulate on its bclts 36a-36c a variable supplyof tobacco leaf laminae for delivery to the blending unit 33 through theprocessing apparatus 30 and belt 32. The belt I and motor 5 constitutemeans for admitting to the recirculating conveyor or feeder 36 tobaccoleaflaminae at a rate which is a function of the quantity of material onthe belts 360-361, the determination of the supply of laminae on thebelts 36a-36c being carried out by the level-sensing device 38.

The parts 32, 40, 53 constitute a second proportioning unit in theconveyor line 3 and the weighing conveyor 40 constitutes the measuringmeans of this second proportioning unit. Its function is to control theoperation of the proportioning unit I in the conveyor line 4 as well asto simultaneously control the feeder (belt 32) of the secondproportioning unit.

The second conveyor line 4 accommodates the aforementioned proportioningunit 4| which is a functional equivalent of the proportioning unit 2010in FIG. I and includes the weighing conveyor 43 arranged to receivetobacco from the automatic feeder 42. The regulator or speed changer 44of the proportioning unit 4t includes a signal generator 45 whichreceives impulses from the weighing conveyor 43. The feeder 42 iscapable of storing tobacco and is driven by a variablespeed motor 46.The quantity of tobacco on the feeder 42 is detected by a level-sensingdevice 47 which is preferably ldtTlllCal with the aforementionedlevel-sensing device 38 of the proportioning unit 29. The maximum andminimum level indicators of the sensing device 47 are respectivelyconnected with signal storing units 48, 49. The numeral 50 denotes aralcd-value-setling device which is adjustable by an adjuster 51. Theratcd-valuc-setting device 50 is connected with an averaging circuit 52for the variablc-specd drive motor 46 of the feeder 42 and includes ascale provided with, for example, l gradualions each corresponding to adifferent sequence of rates of tobacco flow. Each selling of theadjuster eorresponds to a different range of tobacco feed rates by thefeeder 42, and only one rated value is selected at a time. The regulator44 further comprises a timer 55 which is arranged to permit passage ofsignals from the storing units 49, 50 at predetermined intervals, forexample, at 50-seeond intervals. If the minimum level indicator of thelevel-sensing device 47 causes the storing unit 49 to send a signal viatimer SS and on to the ratcd-value-setting device 50, the output signalof the device 50 is changed to correspond to that for the nearest lowerrate of tobacco feed. Such setting remains unchanged until after theelapse of the next fill-second interval. If, after the elapse of suchinterval, the timer 55 again transmits a signal coming from the storingunit 49 which receives signals from the minimum level indicator in thelevel'sensing device 47, the signal coming from the device 50 is changedagain to the nearest lower rate of tobacco feed, and so forth until theminimum level indicator of the sensing device 47 ceases to send signalsvia storing unit 49.

If the timer 55 transmits to the rated-valuc-selting device 50 a signalwhich is generated by the maximum level indicator of the lcvel-sensingdevice 47 and is transmitted by the storing unit 48, the output signalof the device 50 is changed to correspond to the nearest higher rate oftobacco feed. Such mode of operation repeats itself until after thestoring unit 48 ceases to transmit signals at -50-sccond intervals.Depending on the momentary selling of the adjuster St, therated-value-sctting device 50 adjusts the averaging circuit 52 for themotor 46 of the feeder 42. The signal which is transmitted to theaveraging circuit 52 is a composite signal and is also influenced by thesignal generator 45 associated with the weighing conveyor 43.

The position of the adjuster 51 need not be changed in response toadmission of signals from .the storing units 48, 4)v The arrangement issuch that a first setting of the adjuster 5| causes theratcd-valuc-setting device 50 to furnish if) different tobacco feedrates which change automatically in response to signals from the storingunit 48 or 49. If the adjuster St is reset, the device 50 will furnishto different tobacco feed rates. The programming of IO feed rates foreach setting of the adjuster St is done in advance.

The averaging circuit 52 for the motor 46 of the feeder 42 in theproportioning unit 41 is further controlled by the speed changer orregulator 53 for the motor 35 in such a way that, when the weighingconveyor 40 detects a relatively low rate of tobacco feed on the belt32, the speed of the feeder 42 is reduced accordingly, and vice versa.The exact construction of the timer 55, rated-value-sctting device 50and indexing device forms no part of the present invention.

The operation of the blending machine shown in FIG. 5 is as follows:

The bridge circuit 7 is adjusted in accordance with the desired averagevalue of the ratio of the two tobacco types which are to be fed by theconveyor lines 3 and 4. The setting of the bridge circuit 7 is afunction of the width of the belts l, 2 and of the thickness of tobaccolayers on the upper stringers of such belts. The operators then startthe motor 35in a first step and the motors 5, 6 in a next-followingstep. The speed changer 39 of the first proportioning unit 29 in theconveyor line 3 becomes effective and causes the motor 5 to rotate at ahigh speed because it receives a signal from the minumum level indicatorof the level-sensing device 38. The bridge circuit 7 causes the motor 6to drive the belt 2 at a high speed which is a function of the speed ofthe motor 5. it is assumed that the belt I supplies stemmed tobacco andthat the belt 2 Supplies ribs or stems. The two tobacco types weretreated separately during passage through one or more processingapparatus upstream of the belts l and 2. These belts may constilutc thetravelling bottom walls of boxes or bins which contain substantialsupplies of the respective tobacco types. The hells l, 2 withdrawtobacco from the respective bins at a conslant rate per unit of time;such rate depends on the speed of the motors 5 and 6. Stemmed tobaccodrops at the discharge end of the belt I and is conveyed by the beltsIA, 18 toward the inlets of the cutting machines 37 in the processingapparatus 30 at a rate which is slightly in excess of the requirementsof the cutting machines. Such slightly higher rate of tobacco feed isdetermined by the speed changer 39 because the latter continues toreceive signals from the minumum level indicator of the level-sensingdevice 38. Shredded tobacco issuing from the cutting machines 37 travelswith the belt 32 an is weighed by the conveyor 40 prior to reaching theblending unit 33.

The surplus of stemmed tobacco which cannot citler the cutting machines37 continues to travel with the upper stringer of the belt IB and istransferred onto the first belt 360 of the recirculating conveyor 36. Ifthe surplus of stemmed tobacco is substantial, the maximum levelindicator of the levelsensing device 38 sends a signal to the speedchanger 39 and the latter reduces the speed of the motor 5 for the beltI. The bridge circuit 7 then reduces the speed of the motor 5 resultingin a greatly reduced feed of stemmed tobacco, the surplus which isrecirculated by the conveyor 36 is reduced to such an extent that thespeed changer 39 receives a signal from the minimum level indicator ofthe level-sensing device 38 and increases the speed of the motor 5.

When the motor 5 is started, the belt 1 immediately begins to conveystemmed tobacco toward the belt IA. However, the motor 6 is started witha certain delay following starting of the motor 5, and such delay isdetermined by the delay or timelag unit II in the bridge circuit 7. Theadjuster 13 will adjust the delay unit 12 in such a way that theresulting delay plus the time required by successive increments of ribsto travel from the belt 2 to the belt 32 of the conveyor unit 4 equalsthe time required by successive increments of tobacco to advance fromthe belt I to the point where shredded tobacco mixes with the ribscoming from the belt 3| l3. Due to the provision of cutting machines 37,tobacco which is fed by the belt I requires more time to reach the pointwhere its shredded particles mix with tobacco ribs.

Ribs which are fed by the conveyor belt JIA can pass through theproportioning unit 41 at a rate which is determined by the regulator orspeed changer 44. Such ribs then mix with shredded tobacco on the belt32 and are finally blended with shredded tobacco in the blending unit33. in other words, the blend which is advanced by the common conveyorbelt 34 contains a mixture of ribs and tobacco shreds in a predeterminedratio.

If the proportioning unil 4| delivers ribs at a relatively high rate perunit of time, the ratio of ribs to tobacco shreds in the blending unit33 increases provided. of course, that the rate of tobacco feed by thebelt 32 remains unchanged or decreases. The reverse occurs if theproportioning unit 4! reduces the rate at which the weighing conveyor 43delivers ribs to the belt 318. Such changes in the ratio of ribs toshredded tobacco reflect fluctuations in the rate of delivery of theconveyor units 3 and 4. However, the ratio of ribs to shredded tobaccocan change for other reasons too. All such fluctuations in the ratio ofribs to shredded tobacco are reduced or eliminated by the weighingconveyor 40 in the conveyor line 3 and by the proportioning unit 4| inthe conveyor line 4. Rapidly occuring fluctuations in the rate at whichthe belts l and 2 supply the respective tobacco types are often due tothe manner in which the respective tobacco types are stacked or arrayedon the upper stringers of the belts l and 2 and/or in the bins whichfurnish tobacco to these beltsv Furthermore, fluctuations in the rate atwhich the belts l and 2 supply tobacco types can also develop due topeculiari ties of processing apparatus which treat stemmed tobacco andribs prior to admission into the respective bins. The effect of suchrapidly occurring fluctuations can be readily reduced or eliminated bythe machine of FIG. so that, at the very worst, the ratio of shreddedtobacco to ribsjn the blending unit 33 will change very slowly. Themagnitude of fluctuations of the ratio of tobacco shreds to ribs can besiblected in advance by appropriate adjustment -of therated-value-setting device 50 through the intermediary of the adjusterSl.

Fluctuations which are due to irregularities in the operation of thecutting machines 37 cannot affect the ratio of ribs to shredded tobaccoin the blending unit 33. Such fluctuations merely cause fluctuations inthe rate at which the blend advances with the upper stringer of the belt34 because the weighing conveyor 40 controls the regulator or speedchanger 44 for the proportioning unit 4| in the conveyor line 4 in thesame way as described for the weighing conveyor 2lll4 and regulator orspeed changer 2013 of FIG. I. In other words, the weighing conveyor 40measures the quantity of tobacco shreds and causes the proportioningunit 4] to feed ribs at a rate which remains a function of the rate ofdelivery of shreds to the blending unit 33.

As stated before, the delay or timelag unit l2 of the bridge circuit 7causes the motor 6 to drive the belt 2 with a certain delay followingstarting of the motor 5 for the belt I. Furthermore, the delay unit 12causes the motor 6 to change its speed with a delay following anychanges in the speed ofthe motor 5.

The machine of FIG. 5 is clearly analogous to the machine represented bythe flow sheet of FIG. I with the t the proportioning unit 29 regulatesthe rate of tobacco delivery toward the processing apparatus 30 whichcorresponds to the apparatus 2008 and/or 2009 of FIG. I. The weighingconveyor of FIG. I corresponds to the conveyor 40 of FIG. 5, and theproportioning unit 2010 of FIG. I corresponds to the unit 41 of FIG. 5.The feeder 20I I, weighing conveyor 2012 and regulator or speed changer2013 of FIG. I respectively correspond to the feeder 42, conveyor 43 andregulator or speed changer 44 of FIG. 5. The conveyor line 4 of FIG. 5does not contain any processing apparatus such as would correspond tothe apparatus 2006 and/or 2007 of FIG. I.

Of course, the timclag or delay unit I2 of FIG. 5 is needed only if thetime required by successive increments of ribs to cover the distancefrom the belt 2 to the discharge end of the belt SIB is less than thetime required by tobacco discharged from the belt I to reach the pointwhere it mixes with ribs on the belt 32. The motor 6 will be arrestedwith a delay following stoppage of the motor 5, and such delay is againdetermined by the delay unit 12 in the bridge circuit 7.

The aforedcscribed mode of operation of the motor 6, namely, thatchanges in its speed take place with a certain delay following changesin the speed of the motor 5 constitutcs an optional feature of thepresent invention. It is equally possible to construct the bridgecircuit in such a way that it merely causes the motor 6 to start andstop simultaneously with the motor 5. Such modified blending machine isshown in FIG. 6 which illustrates only those parts of the modifiedmachine that are necessary for full understanding of its operation. Thebelts ml, 102 of the two conveyor lines 103, I04 and the motors I05, I06respectively correspond to the parts I, 2, 3, 4 and S, 6 of FIG. 5. Thebridge circuit I07 constitutes a speed changer for the motor I06 ofthebelt I02 but does not control the starting and stoppage of this motor.The speed-reducing transmissions for the sliders IIO, III are shown at[01a, [01b and the elements I08III, II4, IIS, "8, I19 of the bridgecircuit I07 are functional equivalents of similarly numbered elements inthe bridge circuit 7 of FIG. 5. The delay or timelag unit I2 of FIG. 5is replaced by a delay or timelag unit I60 which is connected betweenthe transmis sion [01a and the motor I06. The delay unit I60 may be adjusted by a manually operable adjuster l6], and this delay unit servesto start the motor 106 with a delay which has been selected in advanceby the adjuster I6l. The rotational speed of the motor I06 is adjustedby the bridge circuit 107 in the same way as described in connectionwith FIG. 5 but without any delay, i.e,. all changes in speed of themotor 106 coincide with corresponding changes in speed of the motor I05.If the motor I05 is arrested, the motor I06 continues to run at apreselected basic spe'iid. The means for arresting the motor I06includes a detector or scanner I62 which is mounted adjacent to the beltI02 or I02A and opens the circuit of the motor I06 by conventionalmeans, such as a relay I63, when it detects that the respective belt isfree of ribs. The detector I62 is preferably located in the path of ribswhich are being showered from the discharge end of the belt I02 onto theupper stringer ofthc belt I02A.

FIG. 7 illustrates a digital speed changer circuit 67 for regulating theratio at which the bolts 61, 62 of two conveyor lines feed two tobaccotypes, for example, stemmed tobacco and tobacco ribs. The belts 6], 62are respectively driven by variable-speed electric motors 65, 66 and theregulator or speed changer for the motor 65 is shown at 99. This speedchanger 99 corresponds to the speed changer 39 of FIG. 5. The edgeportions of the belts 6], 62 are respectively provided with equidistantreflectors 70, 7| which are scanned by photoelectric detectors 72, 73.The detector 72 com prises a light source 74 which directs a beam oflight against successive reflectors 70 and an electronic receiver 77whose output is connected with a sum and difference counter circuit 79of conventional design. The detector 73 comprises a light source 76which directs a beam oflight against successive reflectors 7I and thethus reflected light impinges upon an electronic receiver 78 whoseoutput is also connected with the counter circuit 79. The two inputs ofthe counter circuit 79 are shown at a and h and the output c of thiscounter circuit is connected with a signal amplifier 80 which regulatesthe speed of and starts the motor 66 for the belt 62. Signals receivedat the input a from the detector 72 cause the counter circuit 79 to adda digit, and signals received at the input b cause this counter circuitto deduct a digit. The difference between the series of signals receivedat the inputs 0 and b is translated into a positive or negative signalwhich is transmitted by the output c and con trols the signal amplifier80. The output of the detector 72 is further connected with anadjustable counter circuit 8t which causes a switch 82 to arrest themotor 66 in response to reception of a predetermined number of signalsfrom the receiver 77.

The operation of the blending machine which embodies the structure ofFIG. 7 is as follows:

In the first step, the counter circuit BI is adjusted to actuate theswitch 82 in response to reception of a predetermined number of signalsfrom the detector 72, i.e., the counter circuit 81 will determine theoverall length of the tobacco layer which is to be fed by the belt 62.The motor 65 is started and the receiver 77 transmits signals to thecounter circuits 79 and 8|. The number of successive signals received atthe input a of the counter circuit 79 increases rapidly and the latterthen causes the signal amplifier 80 to start the motor 66 for the belt62. The reflectors 71 are set in motion and the receiver 78 sends to theinput I; a series of signals which influence the speed of the motor 66so that the ratio of speeds of the belts 6i, 62 remains within apredetermined range. Fluctuations in the speed of the belt 6I bringabout immediate changes in the speed of the belt 62 because the outputsignal of the counter circuit 79 is a function of the number ofsignalsreceived at the inputs 0 and 1). Furthermore, the counter circuit 81insures that the belt 62 is arrested after having delivered apredetermined quantity of tobacco.

FIG. 8 illustrates a portion of a further blending machine whichincludes a conveyor line comprising an endless belt 222 locateddownstream of a proportioning unit corresponding to the unit 20I0 ofFIG. I, to the unit 2032 of FIG. 2, or to the unit 4I of FIG. 5. Thisproportioning unit comprises a weighing conveyor 210 which receivestobacco from a feeder including two endless belts 202, 224, and a speedchanger or regulator including an averaging circuit or junction 239, avariable-speed motor 250 for the belts 202, 224, and a composite signalamplifier assembly 2" for the motor 250. The

belt 202 serves to convey a variable supply of tobacco, and the belt 224has an upwardly inclined upper stringer which receives tobacco from theupper run of the belt 202 and cooperates with rotary refuser wheels 227to discharge an equalized tobacco layer onto the upper stringer of theweighing conveyor 2I0. The conveyors 2 I0, 222 are driven by a motor 207which is controlled by a manually adjustable speed changer 228.

The quantity of tobacco stored on the belt 202 of the automatic feederis scanned by a level-scnsing device ZOI which includes a minimum levelindicator 23], a maximum level in dicator 232 and two signal-storingunits or bins 237. 238.

The signal amplifier assembly 2 for the motor 250 in cludes apreamplifier 248 and a second amplifier 249, described below. Theweighing conveyor 2l0 is connected with a signal generator 209 whoseoutput is connected to the circuit averaging junction 239. This junctioncompares signals coming from the storing units 237. 238 with signalscoming from the signal generator 209 and from a rated-valuwseltingdevice 208, and sends signals to the preamplifier 248 of the signalamplifier assembly 2I Iv The rated-value-setting device 208 comprises apotentiometer 240 whose slider 24] is connected with thejunction 239.The potentiometer 240 can constitute the signal generator associatedwith a weighing conveyor in another conveyor line of the blendingmachine. With reference to FIG. 2. the potentiometer 240 could beadjusted by signals received from a weighing conveyor corresponding tothe weighing conveyor 2034, it being assumed that the weighing conveyor2l0 of FIG. 8 corresponds to the weighing conveyor 2037 of FIG. 2. Ifthe weighing conveyor 210 of FIG. 8 is to replace the conveyor I2 of HG.I. the potentiometer 240 could be adjusted by the weighing conveyor20l4.

The minimum level indicator 23l ofthe level'sensing device 20] above thebelt 202 comprises a light source 234 and a photosensitive receiver 235which is connected to the input a of the storing unit 237 and 'to theinput I; of the storing unit 238. The maximum level indicator 232comprises a light source 233 and a photoelectric receiver 236 connectedto the input b of the storing unit 237 and to the input a of the storingunit 238. Signals transmitted to the inputs 0 of the storing units 237,238 cause theseunits to transmit signals to the circuitaveragingjunction 239, and signals received at the inputs h of thestoring units 237, 238 cause these units to erase the previouslyreceived signals. Such signal-storing units are known and, therefore,the exact construction of the units 237, 238 forms no part of thepresent invention. The circuit averaging junction 239 regulates thethroughout of tobacco (quantity per unit oftimc).

The minimum level indicator 23] sends a signal when the receiver 235 isfree to receive light from the source 234. The maximum level indicator232 sends a signal when the tobacco on the belt 202 interrupts the lightbeam between the source 233 and receiver 236. Ifthc supply of tobacco onthe belt 202 shrinks to such an extent that the light beam issuing fromthe source 234 is free to reach the receiver 235, the storing unit 237sends to the junction 239 a signal which is added to the signal comingfrom the potentiometer 240 of the ratcdwaluesetting device 208. The unit237 stores such signal from the receiver 235 and continues to send anappropriate signal to the junction 239 until the signal is erased inresponse to reccption of a signal at the input b, such signal beinggenerated by the maximum level indicator 232 when the supply of tobaccoon the belt 202 rises so that the accumulated tobacco inter rupts thelight beam coming from the source 233 and normally impinging upon thereceiver 236. Of course, and when the receiver 235 sends a signal to theinput a of the storing unit 237, it also sends a signal to the input bof the storing unit 238 whereby the latter ceases to send signals to thejunction 239. i.c.. this junction can receive a signal from the storingunit 237 or 238 but never from both storing units at the same time.

When a signal coming from the receiver 236 of the max imum levelindicator 232 erases the signal from the storing unit 237, the storingunit 238 begins to transmit a signal to the junction 239. Such signal isdifferent from the signal transmined by the storing unit 237 so that thespeed ofthe motor 250 is then changed accordingly.

Signals transmitted by the storing units 237. 238 are on posed bysignals produced by the signal generator 209. This signal generatorcomprises a potentiometer 243 having it slider 242 which is connected tothe junction 239. The weighing conveyor 2l0 comprises a verticallymovable platform 2l3 which is connected with the slider 242 by a linkage244 having a pivot 245. The slider 242 is permanently biased to one endposition by a return spring 246. The shaft of the slider 242 is shown at247. The potentiometer 243 may be provided with a graduated scale andthe slider 242 may be used to operate a pointer which moves in front ofthe scale to allow for visual observation of measurements carried out bythe weighing conveyor 2I0.

The second amplifier 249 of the signal amplifier assembly 2| l comprisescontrol coils 249a, 249!) which convey currents whose strength is afunction of signals transmitted by the stor ing units 237, 238.Consequently, the working coils 249e, 249d will provide differentvoltages for the motor 250 which is a DC motor and whose speed is afunction of such changes in voltage. The arrangement is such that thebelt 202 continues to accumulate tobacco until the maximum levelindicator 232 sends a signal to the storing unit 238 and that the supplyof tobacco on the belt 202 thereupon decreases until the minumum levelindicator 23| sends a signal to the storing unit 237. In other words.the supply of tobacco on the belt 202 fluctuates between a minimum and amaximum value but invariably remains within a preset range.

In many instances, different tobacco types require vary long or veryshort intervals to advance from the respective source to the blendinglocation. The length of such intervals will depend on the type oftobacco. on the capacity of processing apparatus which are used intreatment of tobacco, on the construction of the conveyor lines. on thenumber of processing apparatus in a conveyor line. and on certain otherfactors. FIGS. 9 to 12 illustrate blending machines which areconstructed and assembled with a view to compensate for such differencesin conveying times.

Referring to FIG. 9, there is shown a portion of a blending machinewhich comprises a first conveyor line I001 for Virginia tobacco and asecond conveyor line l07I for Oriental tobacco. As stated before.preliminary treatment of Oriental tobacco is much simpler and consumesless time than the treatment of other tobacco types. The conveyor lineI00! for Virginia tobacco comprises three sections 1002, I003, I004. Themedian section I003 comprises an endless receiving bclt I084 which is atakeoff belt and serves to ad vance the tobacco from the processingapparatus in the section I003 to apparatus in the section 1004. Thismedian section I003 comprises three portions 10030, I003b, 1003c whichrespectively include endless belts I088, I089 and I09I. The belt I091serves to feed tobacco into a processing apparatus I006 which is used tomix tobacco with casing or flavoring solution. A similar apparatus isdisclosed in the aforementioned US. Pat. No. 3.4 l 9,0 l 5, toWochnowski. The output of the processing apparatus I006 (hereinaftercalled mixer for short) descends onto the aforementioned dischargingbelt I084 and is advanced toward one or more further processingapparatus in the section I004. The drum I006d of the mixer I006 isrotatable about an axis which is slightly lined with reference to ahorizontal plane and is driven by a variablcspced motor 1007. This motor1007 also drives the belt I09l. The mixing zone in the interior of thedrum l006d receives casing from the atomizer nozzle of a conduit [006awhich is connected with a tank l006b and contains a variable-deliverypump I006c. The arrow I008 indicates the direction in which the casingfiows when the pump I006c is in operation. The conduit [006a furthercontains an adjustable metering valve I009 which is regulated by a speedchanger or regulator I0ll for the motor I007. The speed changer l0ll isfurther connected with a moisture detector I012 which is installed in oradjacent to the discharging belt 1084 and controls the adjustment ofvalve 1009 as well as the speed of the motor I007. The moisture detectorI012 determines the moisture content oftohacco which has been mixed withcasing and, thercfoi'e. the measurement carried out by detector 1012 isindicative of the intensity or thoroughness of mixing action which takesplace in the drum l006d. The moisture detector I012 comprises capacitormeans 1012a forming part of an oscillator circuit (not shownl whosefrequency may be changed periodically by a nonillustrated variablecapacitor. The variations in high frequency oscillations are induced bychanges in moisture content and are measured to determine such moisturecontent.

The supply conveyor 1091 which delivers tobacco to the drum 100611 ofthe mixer 1006 is associated with a detector or sensor 1013 whichdetermines the throughput of tobacco and is connected with a signalgenerator I014. The detector ll3 may be constituted by a photoelectriccell assembly which sends a signal when the conveyor belt 1091 ceases todeliver tobacco. The signal generator 1014 has a first output 1016 whichsends a signal when the detector I013 produces a signal indicating thatthe delivery of tobacco by the belt 1091 is let minatcd, and a secondoutput 1017 which sends signals in the absence ot'a signal from thedetector 1013v The signal generator 1014 may comprise a light-sensitiveelectrtmic receiver. The outputs 1016, 1017 are respectively connectedwith two amplifiers 1018, 1019 whose outputs are connected with atwo-way switching device 1021. The switching device 1021 has a singleoutput which is connected with the speed changer or regulator 1011. Athird input ofthe switching device 1021 is connected with arated-value-setting device 1022 which can be set by a manually operatedadjuster 1023. The rated-value setting device 1022 controls the speedchanger 1011. The fourth input of the switching device 1021 is connectedwith an arresting switch 1024 which can arrest the motor 1007 simul'taneously with closing of the valve 1009.

The switching device 1021 can be moved to two positions In one of itspositions. it connects the rated-value-sctting device 1022 with thespeed changer I011 when the signal generator I014 sends signals throughthe amplifier 1019 (i.c., when the belt 1091 delivers tobacco to thedrum 100611). In the other position of the switching device 1021, thearresting switch 1024 is connected in circuit with the speed changer1011 and the latter arrests the motor 1007 because the switching device1021 receives a signal from the signal generator 1014 via amplifier1018. The arresting switch 1024 then efl'ects closing of the valve 1009.

The operation ol'thc mixer 1006 is as follows:

When the detector I013 determines that the belt 1091 does not supplytobacco into the drum 1006d, the signal generator I014 sends a signalvia amplifier 1018 and such signal causes the switching device 1021 toconnect the speed changer 101 l in circuit with the arresting switch1024 so that the valve 1009 is closed and the motor 1007 is at astandstill. Prior to admission ofa fresh charge of Virginia tobacco tothe belt 1091, the rated-value-sctting device 1022 is set by theadjuster 1023 to insure that each increment of tobacco will be mixedwith a predetermined amount of easing. When the freshly admitted charge(coming from the belt 1089 in the portion 10031; of the conveyor linesection 1003) reaches the belt 1091, the detector I013 sends a signal tothe signal generator 1014 and the latter sends to the switching device1021 a signal via output 1017 and amplifier 1019. It should be notedthat the detector 1013, as seen in FIG. 9, is of necessity so positionedthat it would react to the flow of particles onto the conveyor 1091 fromthe conveyor 1089. The switching device 1021 then connects therated-valuc-setting device 1022 with the speed changer I01] and thelatter Opens the valve 1009 and starts the motor 1007 for the druml006d. The arresting switch 1024 is then disconnected from the speedchanger The throughput of the valve 1009 and the speed of the motor 1007will depend on the setting of the rated-valuesetting device 1022, andthe motor 1007 continues to drive the belt 1091 and the drum 1006d untilthe detector 1013 sends a signal in dicating that the charge of tobaccohas been consumed. The arresting switch 1024 then stops the motor 1007and effects closing ofthe valve 1009 in a manner as described above.

The portions 1003b and 1003!: of the conveyor line section 1003accommodate other processing apparatus. For example. and as shown inFlCl 9, the portion 1003b accommodates a stripping or destalking machine10250 which is associated with a pneumatic separator 1025. A similarcombination is disclosed, for example, in US. Pat. No. 3,205,209 grantedto Wochnowslti et al. on Aug. 9, 1966. The portion 1003a accommodates amoistening apparatus 1026 for tobacco leaves. This apparatus is similarto the mixer 1006 with the exception that the atomizer nozzle of itsconduit 1026a discharges water, steam or another suitable moisteningagent.

The stripping machine 1025a comprises a rotary drum 1025!) whose bladesdestalk tobacco leaves in cooperation with a fixed basket and which isdriven by a variable-speed motor 1025/. The mixture of tobacco leaflaminae and ribs issuing from the machine 1025a enters the housing 1025cof the separator 1025 wherein the ribs are segregated from laminae. Theribs drop onto a takeoff belt 1025c and the laminae descend onto theaforementioned belt 1089. The separator I025 comprises a closedpneumatic circuit which contains a suction fan 1025d driven by a motor1025:. The hopper of the stripping machine 1025a receives moistenedtobacco leaves from a conveyor belt 1083. The motors 1025c, 1025] can bestarted and arrested by a system of switches mounted on a control panelI02Sg. This control panel receives signals from a detector or sensor 162which is adjacent to the upper run of the belt 1083. If the detector 262determines the presence of tobacco leaves on the belt 1083, it causesthe switches on the control panel 10253 to start the motors 1025:,I025]. The detector 262 also sends signals which disconnect the motors1025c, 1025ffrom the source ofelectrical energy.

The component parts of the moistcning apparatus 1026 in the portion1003a of the conveyor line section 1003 are analogous to the pans of themixer 1006 and are denoted by similar reference numerals. For example,the numerals 1026d, 1029, 1031 respectively denote a rotary drum, anadjustable valve and a speed changer.

The second conveyor line 1071 for oriental tobacco comprises threescctions 1072, 1073, 1074. The first section 1072 merely contains a belt1096 (or a series of bells) serving to deliver Oriental tobacco from asource to a belt 1097 in the section 1073. The belt I097 suppliestobacco into the drum 1076d of a moistening apparatus 1076 which issimilar to the moistening apparatus 1026 and mixer 1006. The drum [076dis driven by a variable-speed electric motor 1077 which also drives thebelt 1097 and is connected with a speed changer or regulator 1087. Thecontrol system of the moistening ap paratus 1076 further includes amoisture detector 1082 which is adjacent to a discharging belt (servingto deliver tobacco to the section 1074) and is connected with anaveraging circuit or junction 1081. The latter controls an adjustablemetering valve 1079 in the conduit which admits water or steam to themixing zone of the drum 1076d. The junction 1081 is further connectedwith the slider of a potentiometer I092 forming part of arated-valuesetting device. The speed changer 1087 starts and arrests themotor 1077 in response to signals received from the detector 1013 in thesection 1003 of the conveyor line 1001 for Virginia tobacco.

The processing apparatus 1006, 1025-10250, 1026 and 1076 are started andarrested in automatic response to signals received from detectors I013,262, 1033, i.e., as a function of the tobacco feed. Of course, thetravel of Virginia tobacco through processing apparatus 1006,1025-10254, 1026 requires more time than the travel of Oriental tobaccothrough the single processing apparatus 1076. In order to avoid theutilization of bulky and costly intermediate magazines for Orientaltobacco upstream of the blending location where the conveyor lines 1001and 1071 of FIG. 9 meet. the detector 1013 in the portion 1003c of theconveyor line section 1003 for Virginia tobacco controls the speedchanger 1087 for the motor 1077 and belt 1097 of the processing apparatus 1076 for Oriental tobacco. The speed changer I087 starts themotor 1077 when the detector I013 senses the presence of Virginiatobacco on the belt 1091. Thus, the rate at which the discharging bclt1089 delivers Oriental tobacco from the section 1073 to the section 1074of the conveyor line 1071 varies in the same way as the rate at whichthe belt 1084 delivers Virginia tobacco from the section 1003 to thesection 1004 ofthe conveyor line 1001 despite the fact that preliminarytreatment of Virginia tobacco consumes much more time than preliminarytreatment of Oriental tobacco. The ratio of Virginia tobacco to Orientaltobacco can be selected in the same way as described in connection withFIGS. to 7. The belts I, 2 of FIG. 5 would correspond to the belts 1084and 1098 oI'FlG. 9.

Of course, a tobacco stream or mat will require a certain amount 01'time to advance from a detector to the associated processing apparatus.For example, a certain amount of time will elapse between detection ofVirginia tobacco leaves by the detector 1033 in the portion 1003a of theconveyor line :cction I003 of FIG. 9 and the entry of such leaves intothe as sociatcd moistening apparatus 1026. Such rime span can beaccounted for or considered by arresting the respective processingapparatus with a delay corresponding to the time interval required by anincrement of tobacco on the belt 1088 to advance from the detector 1033into the mixing zone ofthe drum I026d. A :uitable delay or timelag unit1020 associated with the detector 1013 is indicated schematically in thecircuit of the processing apparatus or mixer 1006 of FIG. 9, and asecond delay unit 1040 is shown in circuit of the moistening apparatus1026. The delay unit 1020 can be installed between the amplifier I018and the two-way switching device 1021 and is indicated by broken line:because it constitutes an optional feature of the blending machine. Thesame applies for the delay unit 1040. For example. the delay unit 1020can be built into the speed changer 1011 for the motor 1007. It is clearthat the circuit! of the processing apparatus 1025-10250, and 1076 canbe provided with analogous delay or timelag units.

If the delay unit 1020 of FIG. 9 delays only the stoppage of the motor100), the mixer 1006 will be in operation but will receive no tobaccoduring the interval required by tobacco lhrcd: to advance from thedetector 1013 to the mixing zone in the drum I006d. Such short-lasting"dry" run of the mixer I006 does no harm.

In the blending machine of FIG. 9. the rated-value-sctting device 1022in the circuit of the mixer 1006 can be lot by the adjulter I023. Thesetting lelected by the manually operated adjuner 1023 will be effectivewhen the tobacco :hredt enter the portion 1003: of the conveyor linesection 1003. The setting of the device 1022 for a fresh charge oftobacco can be changed lublequent to transport of the preceding chargebeyond the drum I006d. If it i: desired to process charges of differenteon:l:tencie: in rapid sequence. the time allotted for manual operationof variou: adjulters (1023, 1043) will be rather :hort.

FIG. 10 lllultratel diagrammatically a blending machine wherein theproceuing lpparatu: can be properly reset or adjulted for proceuing ofone or more freuh charger of tobacco while the preceding charge it :tillin the procers of undergoing treatment on it: way to the blendinglocation. The setting for treatment of next-following charge: doe: notaffect the treatment ofthe running charge. In the diagram of FIG. 10.all such part: which are clearly analogous to or identical to the partsdclcribed in connection with FIG. 9 are denoted by :imiltir referencenumeral: railed by 100. Thu, the mixer 1106 of FIG. 10 correlpond: tothe mixer 1006 of FIG. 9. The blending machine which I: :hownlcltematically in FIG. 10 further comprile: a locking unit 1157 which i:installed between the two-way :witchlng device 1121 and the rated valuesetting device 1122. The output of the locking unit 1157 I: connectedwith the amplifier 1119. and this locking unit 1157 comprises 1 timerI158 adapted to be set by a manually operated adjuater I159. The lockingdevice 1157 also comprire: storing device 1161 for signals received fromthe rated-value-setting device 1122. The timer 1158 is connected betweenthe ampli- Her 1119 and the storing device 1161, and the latter isconnected between the rated-value-sctting device 1122 and the two'wayswitching device 1121. The adjuster 1159 can set the timer 1158 and thelatter counts time only when the belt 1191 delivers tobacco past thedetector 1113. In other words, the timer 1158 determines only the lengthof the interval during which the mixer 1106 receives tobacco. Suchinterval is known in advance for a given quantity of tobacco. Theadjuster 1159 sets the timer I 158 for the shortest possible intcrvalwhich is required to complete the treatment of a known charge in themixer 1106. When the signal generator I114 sends a signal via output1116 and amplifier 1118 to indicate that the delivery of tobacco iscompleted prior to elapse of the anticipated interval (setting of timer1158 by adjuster 1159). such signal indicates that the operation of themachine is not satisfactory. The machine is then arrested prior tocompleted treatment of the charge. The manner in which a signal comingfrom the output 1116 and amplifier 1118 can arrest the mixer 1106 is thesame as described in connection with FIG. 9. The same holds true for themanner in which a signal coming from the signal generator 1114 viaoutput connection 1117 and amplifier I119 restarts the mixer I106. Thetwo-way switching device 1121 then receives signals from thesignal-storing device 1161 independently of the rated-value-settingdevice I 122 and sends signali to the speed changer or regulator 1111for the motor 1107. The storing device 1161 blocks the passage ofsignals from the rated-value4etting device 1122 if such signals aredifferent from those transmitted by the storing device 1161. The latterwill cease to transmit signals upon elapse ol' the interval selected bythe adjuster 1159 for the timer 1158 and upon reception from detector1113 of: signal that a fresh charge of tobacco is being led to the mixerI106. The operation of the speed changer 1111 i: then controlled bysignals from the rated-vaIue-ttetting device 1122 which can transmit thesame signals as before or difl'erent signals, depending upon whether ornot the adjuster 1123 was reset during the interval when the moodchanger [III was receiving signals from the storing device 1161.

The timer 1158 is reset to zero when the speed changer II 11 receives:ignalti from the rated value letting device 1122 and begins to count I:new interval which can be the same as the previously counted interval orit different interval, depending on the :hortettt anticipated timerequired for processing of the charge which it! being fed into the drumof the mixer I106. The setting of the timer 1158 i: carried out by theadjuster 1159.

It will be men that the rated value: of signal: which will control the:peed changer 1111 during treatment of the next-fob lowing charge can belelected before a charge ha: completed its advance through the mixer1106 and while the charge which travels through the mixer I: treated inaccordance with a recipe which might but need not be the :umc u therecipe for the next-following charge. In other word:. the locking unit1157 :crve: to program the blending machine for a future ope rationwhile the machine it in actual me. It i: also poasible to select inadvance two or more future operation: of the machine it the manuallyadjunable timer 1158 is replaced with a programmable timer. Alto, themachine of FIG. 10 may be equipped with a counter I063 (:hown by brokenlines) which can automatically :top the motor 1107 after elapse ot' apredetermined period of time :elected by a :ultable adjuster I064. Thecounter 1063 it connected directly to the :peed changer IIII and its:lgnal override: the :ignal: coming from the locking unit 1157. Thecounter 1063i: :etin motion in lI-I- tomatic relponle to :tarting oi themotor and Interrupts its count if the operation at the mixer 1106 i:interrupted. Signals to :tart, interrupt and rutart the counter 1063 aret'urnilhed by the :pced changer 1111.

FIG. 11 illuitrnte: schematically l blending machine which comprise:delay or tlmellg device: :crvlng to compensate for different time:required by different tobacco types to reach the blending location andto compensate for times required by a given tobacco type to advance froma detector to the adjoin ing processing apparatus. The numerals I20JA,I288, I283 denote three endless belts forming part ofti conveyor linefor a given tobacco type. A processing apparatus I226 is adjacent to themedian belt I288 and this appai'attis is arranged to perform the samefunction as the moistening apparatus I026 in the left-hand part of FIG.9. A detector I233 is adjacent to the belt I288 upstream of the drum ofthe moistening apparatus I226 which latter is driven by a variable-speedelectric motor I227. Two amplifiers I238, I239 receive signals throughout put lines I236, I237 ofa signal generator I234 which is connectedwith the detector I233. The motor I227 is regulated by a speed changerl23l which however, does not regulate the metering valve I229. Thelatter is regulated by a separate regulator I23IA. The speed changerl23l is connected with a gate I250 which is Connected with arated-value-selting device I242. The regulator I23IA is connected with arated value-setting device I242. The regulator I23IA is connected with adelay or timelag unit I25l, and a gate I252. The rated value settingdevice I23 for the regulator I23IA can be set by a manually operatedadjuster I254. The rated value setting device I242 for the speed changerl23l can he set by an at; juster I234. The numeral I244 denotes anarresting switch which can be connected with the speed changer l23| toarrest the motor I227. The switch I244 can be connected in circuit withthe motor 1227 through a gate I255, a delay or timelag unit I256 and acontrol switch I257.

The valve I229 can he closed through the intermediary ofa delay ortimelag unit 1258 and a gate I259 by an arresting switch I260 which isanalogous to the arresting switch I244. A timer I26l whose input isconnected with the motor I227 has three outputs connected with the delayor timelag units I25I, I256 and I258.

The operation is as follows:

The adjusters I243, I254 will be manipulated to set therated-value-setting devices I242 and I253 in order to select ratedvalves for the speed changer I23l and regulator I23IA. The signalscoming from devices I242, I253 can reach the speed changer I23] andregulator I23IA only when the respective gates I250, I252 are open. Theregulator [231A will receive signals with a delay determined by thedelay or timelag unit I251.

The zero or shutoff signals coming from the arresting switches I244,I260 will reach the speed changer I23I and regulator I23IA only when therespective gates I255, I259 are open. Such signals will be delayed bythe delay units I256 and I258.

The delay unit l25| is set for a delay or interval r which is requiredby an increment of tobacco to advance from the de tector 1233 to theinlet ofthe moistening apparatus I226. The delay unit I258 is set for aninterval 1, which is required by tobacco to cover the distance from thedetector I233 to the moistening zone in the apparatus I226, namely, tothe zone where the tobacco comes in contact with water or steam issuingfrom one or more nozzles (not shown). The delay unit I256 is set for adelay or interval 1, required by tobacco to travel from the detectorI233 to the discharge end of the belt I288. The intervals 1,, r, and tare functions of the speed of the motor I227; therefore, the timer I26!is connected with the motor I227 and receives therefrom signals whosefrequency is a function of the speed of the belt I228 and the speed ofthe drum in the moistening apparatus I226. The timer I26! controls thedelay units I251, I256, I258 in such a way that the intervals 1,, r,, r.are functions of the frequency at which the timer receives impulses fromthe motor I227.

The gates I252, I259, I250 and I255 are controlled by amplifiers I238,I239 in such a way that the gates I255. I259 open only when the signalgenerator I234 sends a signal through the output line I236 and amplifierI23tl, and that the gates I250. I252 open only when the signal comesfrom IIIL output line I237 and amplifier I239, i.e., when the detectorI233 detects the advance oftohacco on the belt I288.

When the belt I288 does not deliver tobacco, the detector I233 causesthe signal generator I234 to send a signal through the output line I236and amplifier I238 so that the gates I255 and I259 are open. The valveI229 is closed by the arresting switch I260 and a control switch I262.The speed changer I23I stops the motor I227 in response to a signal fromthe arresting switch I224 and control switch I257.

lfthe belt 1203A thereupon admits tobacco to the belt I288 (which isidle), the detector I233 sends a signal which causes the gates I255,I259 to close and the gates I250, I52 to open. The control switchesI257, I262 are disconnected from the respective arresting switches I244,I260 but this does hot affect the position of the valve I229 whichremains closed. The rated-value-setting device I242 is connected withthe speed changer I23! because the gate I250 is open whereby the speedchanger I23I starts the motor 1227 without delay at a speed determinedby the ratcd-value setting device I242. The speed changer I231 turns offthe control switch I257. The timer I261 receives from the speed changerI23] impulses at a frequency which is a function of the speed of themotor I227. The belt IZllIl is driven by the motor I227 and begins todeliver tobacco from the discharge end of the belt I203A toward themoistening apparatus I226 while the valve I229 continues to preventadmission of water or steam. Upon elapse of the interval r, signals fromthe rated-value-setting device I253 can reach the regulator 1231Athrough the gate I252 which is open. The regulator I23IA turns off thecontrol switch I262 and opens the valve I229 to the extent determined bythe rated-value-setting device 1253. The valve I229 begins to admitwater or steam which reaches the interior of the moistening drum shortlythereafter. During the interval which elapses while the moistening agentflows from the valve I229 to the nozzle or nozzles in the drum of theprocessing apparatus I226, tobacco reaches the nozzles tie, the intervalr has elapsed) and the circuitry of FIG. II then remains in the justdescribed state until the detector I233 sends a signal which indicatedthe absence of tobacco on the belt 1288. Such signal closes the gatesI250, I252 and opens the gates I255, I259. The speed changer I23I andregulator I23IA are disconnected from the rated-value setting deviceI242, I253 but they continue to control the speed of the motor I227 andthe position of the valve I229 because they have stored the last signalsfrom the devices I242, I253. The motor 1227 continues to run and thevalve I229 remains open. The motor I227 is stopped when the signalcoming from the arresting switch I244 and passing through open gate I255reaches the control switch I257 with a delay determined by the delayunit I256. The valve I229 is closed when the signal coming from thearresting switch I260 through the gate I259 (which is open) reaches thecontrol switch I262. The delay unit I258 permits the signal coming fromthe arresting switch I260 to reach the control switch I262 with a delayt,, i.e., when the last increment of the charge has covered the distancefrom the detector I233 to the spray nozzles in the drum of themoistening apparatus I226. The control switch I262 erases in theregulator I23IA the last signal from the rated-value-setting device[251' When the interval 1 has elapsed, the entire charge has beenconveyed beyond the belt I288 and the delay unit I256 per mits thesignal from the arresting switch I244 to reach the control switch I257which arrests the motor I227 and erases in the speed changer I231 thelast signal from the rated-valuesetting device I242. The timer I261ceases to receive impulses from the motor I227 so that the circuitry isdeenergized. The procedure is repeated in the abovedescribed sequencewhen the detector I233 detects the first increment of a fresh chargecoming from the belt I203A. The motor 1227 will be driven at a speedselected by the rated-valuc-setting device I242 and the valve I229 willopen to the extent depending on the intensity of signals transmitted bythe rated-value-setting device I253. The device I242, I253 may but neednot be reset by adjusters I243, I254, depending on the type of chargeand on the desired moistcning of tobacco in the processing apparatusI226.

In the machines represented by the diagrams of FIGS. and 11, therated-value-setting devices 1022, 1042, 1242, 1253 can be adjusted afterthe respective regulators 1011, 1031 1231, 1231A receive the signalwhich indicates the end of the transport of tobacco. In the machine ofFIG. 10, the rated value-setting device 1122 can be adjusted before thespeed changer or regulator 1111 receives the signal which indicated theend of the transport of tobacco In many instances, the recipe (ie., therate at which a moistening or mixing apparatus admits water, steam,casing or flavoring solution to tobacco must be changed from charge tocharge. In the blending machines represented by the diagrams of FIGS. 9to 11, this would entail adjustment ofthe respective rated value settingdevices after completion or during processing of each successive charge.FIG. 12 illustrates scbc matically a portion of a blending machinewherein a series o1 adjustments of the HIILd VtJIUC-SCIIIHQ means can bescanned in a predetermined sequence so that two or more charges can beprocessed in accordance with a predetermined program even though therecipes for the charges are different. The parts shown in FIG 12 areanalogous to those described iii connection with FIG 9 and are denotedby similar reference numerals with 3110 added to each numeral. Thestructure ot FIG. 12 diffeis from that of II(r. I mainly in that therated value-setting device 1022 (and the ad uster 1023) is replaced witha more sophisticated circuit including a four-pole step by-stepswitching device 1350 having a central contact con nected with one inputof a two way switching device 1321 The four poles of the switchingdevice 1350 are connected with four rated-value-setting devices 1351,1352, 1353, 1354 Each of the devices 1351-1354 can be set by one of fouradjusters1355,1356,13S7,1358,and each ofthese devices cor responds tothe device 1022 of FIG. 9. The numeral 1359 denotes a timer which can beset by an adjuster 1360 and is connected between the amplifier 1319 andswitching device 1350. The timer 1359 corresponds to the timer 1158 ofFIG. 10 and serves to determine the duration of signals coming from theamplifier 1319 (when the belt 1391 feeds tobacco to the processingapparatus 1306] as well as to compare such signals with signals storedtherein in response to setting by the adjuster 1360. If the signalcoming from the output line 1317 and amplifier 1319 indicates that theinterval of feed of a given charge exceeds the anticipated interval(setting by lltc adjuster 1360), the timer 1359 is activated and thenext tobacco" signal from the amplifier 1319 is transmitted to theswitching device 1350 to reset the latter so that the next fol lowingratcd-value-setting device (e.g., 1352) sends signals on to the speedchanger or regulator 1311 for the motor 1307 and valve 1309. At the sametime, the timer 1359 is inactivatcd (insofar as resetting of the device1350 is concerned] and is reset to zero so that it can start to countthe duration of the next interval (delivery of the next tobacco chargeinto the processing apparatus 1306).

The adjuster 1360 selects the interval which is anticipated forprocessing of a charge. The just described mode ofopera' tion isrepeated as often as needed but not more than two more times because theoperating means for the apparatus 1306 of FIG. 12 has a fourratcdwaluesetting devices 1351 1354. The signal to arrest the motor 1307and to close the valve 1309 is generated in the same way as described incon ncction with operation of the processing apparatus 1006 in FIG. 9. Amoisture detector is shown at 1112 in l lti 10, .it 1208 in FIG. 11 andat 312 in FIG. 12, respectively and in each instance the function of themoisture detector and its cooperation with the valves 1109, 1229 and1309 respective ly, is the same as that pertaining to the moisturedetector 1012 and the valve I009 appearing in the upper hand portion ofFIG.

In the blending machines which embody the structures shown in FIGS. 912,differences in time required for treatment of tobacco types in variousrocessing apparatus tttc compensated for in response to signals receivedfrom strategi cally distributed detectors or sensors. Anotherpossibility ol compensating for such differences has been mentioned inF105. 1- 4 which respectively show delay or timelag units 201S2016,2041-2042, 2068-2069 and 2090-2091. These delay units are disposeddownstream of the respective processing apparatus and one thereof isillustrated in FIGS. 13 and 14.

The delay units of FIGS. 13 and 14 comprises an elongated box or bin 401having a superstructure 402 of rectangular outline and includingsidewalls of the bin. The superstructure 402 preferably consists ofwood. The bottom wall of the bin 40] is constituted by the upperstringer of an endless conveyor belt 403 which is trained around rollers404 405. The roller 405 can be driven by a DC motor 406 which isconnected with a source 408 of polyphase alternating current through theintermediary of a rectifier 407. The output voltage of the rectifier 407can be regulated by an adjuster 409. The output shaft of the motor 406drives belts 412, 413, 423 which respectively rotate shafts 414, 415,424 of rake wheels 416, 417, 425. The wheels 416, 417, 425 together forma withdrawing device 422 fcetls tobacco to a takeoff belt 419.

In operation, the supply conveyor 4111 delivers tobacco into the bin 401and onto the upper iitringer of the belt 403. This belt advances tobaccotoward the withdrawing device 422 wh ch feeds tobac co onto the takeoffbelt 419. The speed of the belt 403 can be varied infinitely by theadjuster 409, Le, the belt 403 constitutes with parts 406409 anadjustable delay or timelag unit.

Each of the delay units 2015, 2016 shown in FIG. 1 can comprise a belt403 and the speed of each of these belts can be adjusted in such a waythat the time required by increments of tobacco of the first type toadvance from the proportioning unit 2010 to the blending unit 2004 isthe same as the time required by incrcmcnLs of tobacco of the secondtype to travel from the weighing or measuring conveyor 2014 to theblending unit 2004.

The rate at which the conveyor 418 supplies tobacco into the bin 401 ofFIGS. 13 and 14 depends on the setting of the proportioning unit. Forexample, the conveyor 418 of FIGS. 13 and 14 can correspond to theconveyor which forms part of the conveyor line 2001 in FIG. 1 to delivertobacco from the weighing conveyor 2012 to the delay unit 2015.

As shown in FIG. 2, the conveyor line 2020 does not contain it delayunit. this is due to the fact that this conveyor line delivers tobaccoat a rate which is less than the rate of tobacco delivery by lines 2021,2022. The delay units 2041, 2042 in conveyor lines 2021, 2022 insurethat the average speed of tobacco delivery from the processing apparatus2030 and weighing conveyor 2037 to the blending unit 2024 is the same asfrom the weighing conveyor 2037.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featureswhich fairly constitute essential characteristics of the generic andspecific aspects of our contribution to the art.

What we claim as new and desired to be protected by Letters Patent isset forth in the appended 1. A machine for blending various types oftobacco or like fibrous materials, comprising blending means; at leasttwo conveyor lines for supplying to said blending means different ty esof material; measuring means provided in one of said conveyor lines fordetermining the rate of material flow per unit of time therein and meansprovided in the other conveyor line for regulating the rate of materialflow as a function of the results of measurements carried out by saidmeasuring means.

2. A machine as defined in claim 1, further comprising second materialflow rate regulating means provided in said one conveyor line andincluding said measuring means.

3. A machine as defined in claim 1, wherein said conveyor lines arearranged to supply the respective types of material to said blendingmeans at a constant ratio, said proportioning means comprising feedermeans having a variable supply of the respective material type fordelivery to said blending means and means for delivering to said feedermeans material at a rate which is a function of the quantity of materialin said supply.

4. A machine as defined in claim I, wherein each of said conveyor linescomprises a conveyor for the respective material type, variable-speeddrive means for each of said conveyors, and regulator means forregulating one of said drive means as a function ofthe speed of theother, 'iie means.

5. A machine as defined in claim 4, further comprising at least oneprocessing apparatus provided in said one conveyor line intermediate sadring means and the respective conveyor for subjecting the respectivematerial type to at least one treatment for affecting the rate ofdelivery of material per unit of time toward said measuring means, theconveyor in said one conveyor line being arranged to supply to saidprocessing apparatus material at a rate which at least temporarilyexceeds the capacity of said processing apparatus whereby the processingapparatus refuses the surplus of the thus delivered material,recirculating means for collecting upstream of said processing apparatussuch surplus material which is refused by said processing apparatus, ndspeed changer means for regulating the drive means of the conveyor insaid one conveyor line a s a function of the amounts of refused materialon said recirculating meansv 6. A machine for blending various types oftobacco or like fibrous materials, comprising blending means; at leasttwo conveyor lines for supplying to said blending means different typesof material a measuring device provided in one of said conveyor linesfor determining the rate of material flow per unit of time; aproportioning device provided in the other conveyor line for regulatingthe rate of material flow as a function of the results of measurementscarried out by said measuring device; and timelag means provided in atleast one ofsaid con veyor lines between said blending means and therespective device for regulating the time required by successiveincrements of the respective material to cover the distance between therespective device and said blending means.

7. A machine as defined in claim 6 further comprising at least oneadditional conveyor line for supplying to said blend ing means a furthertype of material, one of said conveyor lines being arranged to deliverone type of said material at a speed which is less than the speed ofmaterial in the remaining conveyor lines, one of said timelag meansbeing provided in each of said remaining conveyor lines.

8. A machine for blending various types of tobacco or like fibrousmaterials, comprising blending means; at least two conveyor lines forsupplying to said blending means different types of material, at leastone adjustable processing apparatus provided in at least one of saidconveyor lines and operative to treat the respective material type;signal-generating detector means for detecting changes in the rate ofsupply of material by one of said conveyor lines; and operating meansfor adjusting said processing apparatus in response to signals from saiddetector means, said detector means and said processing apparatus beingprovided in different conveyor lines.

9. A machine for blending various types to tobacco or like fibrousmaterials, comprising blending means; at least two conveyor lines forsupplying to said blending means different types of material; at leastone first adjustable processing apparatus provided in at least one ofsaid conveyor lines and operative to treat the respective material type;signal-generating detector means for detecting changes in he rate ofsupply of material by one of said conveyor lines; first operating meansfor adjusting said processing apparatus in response to signals from saiddetector means; at least one second adjustable processing apparatusprovided in the other conveyor line and operative to treat therespective material type; and second operating means for adjusting saidsecond processing apparatus in response to signals received from saiddetector means, at least one of said processing apparatus being arrangedto add to a respective material type one or more treating media and therespective operating means comprising rated-value-setting means forselecting said treating media, said rated-value-setting means having aplurality of settings in each of which said ratedwalue-settlng meansselects a different treating medium and said rated-value-setting meansbeing adjustable to select at least one new treating medium while saidone processing apparatus treats a charge of material with a previouslysclectd tf eating medium.

If]. A machine for blending various types of tobacco or like fibrousmaterials, comprising blending means; at least two conveyor lines forsupplying to said blending means different types of material; at leastone first adjustable processing apparatus provided in at least one ofsaid conveyor lines and operative to treat the respective material type;signal-generating detector means for detecting changes in the rateofsupply of material by one of said conveyor lines; first operatingmeans for adjusting said processing apparatus in response to signalsfrom said detector means; at least one second adjustable processingapparatus provided in the other conveyor line and operative to treat therespective material type; second operating means for adjusting saidsecond processing apparatus in response to signals from said detectormeans, at least one of said processing apparatus being arranged to addto a respective material type one or more treating media ad the rcspcutive operating means comprising rate-valuesetting means for selectingsaid treating media; and locking means associated with saidrated-valuc-setting means to prevent changes in the addition of treatingmedia during treatment of a charge of the respective material type andto effect repeated addition of the same treating medium upon completionof the treatment of-a charge.

If. A machine for blending various type of tobacco or like fibrousmaterials, comprising blending means; at least two conveyor lines forsupplying to said blending means different types of material at aconstant ratio; first proportioning means provided in one of saidconveyor lines for regulating the rate of material flow toward saidblending means, said proportioning means comprising feeder means havinga variable supply of the respective material type for delivery to saidblending means, and means for delivering to said feeder means materialat a rate which is a function of the quantity of material in saidsupply; second proportioning means provided in the other conveyor linefor regulating the rate of material flow toward said blending means,said second proportioning means comprising fceder means arranged toaccumulate a variable supply of he respective material type and meansfor evacuating from said last-mentioned feeder means material at a ratewhich is a function of the quantity of material in said last-namedsupply, each of said proportioning means further comprising levelscnsingmeans comprising maximum and minimum level indicators arranged toproduce signals indicative of the quantity of material in the respectivesupply, said second proportioning means further comprising intermediatemeans interposed between the respective indicators and the means forevacuating material from the respective feeder means, said intermediatemeans comprising means for efl'ecting the evacuation of more materialwhen the respective maximum level indicator detects that the respectivesupply is replenished to a maximum value and to effect evacuation ofless material when the respective minimum level indicator detects thatthe respective supply is depleted to a minimum value, said intermediatemeans further comprising rated-value-setting means responsive to signalsproduced by the respective indicators and communicating with means foreffecting a stepwise reduction in the rate of evacuation of materialfrom the respective supply in response to signals from the respectiveminimum level indicator and for effecting a stepwise increase in therate of evacuation of material in response to signals from the respective maximum level indicator.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,590,826 Dated July 6 1971 InVentor(S) Waldemar Wochnowski et a1 It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

On the cover sheet, "[32] Priority May 4, 1966 Germany [3 1] H 59300"shouId read [32] Priority May 4 1966 May 13 1966 May 17 1966 33] Germany[3 H 59300; R 59390; H 59 426 Signed and sealed this 12th day ofSeptember 1972.

(SEAL) Attest:

ROBERT GOTTSCHALK EDWARD M.FLETCHER ,JR.

Commissioner of Patents Attesting Officer uscoMM-oc wave-Poo 9 U 5GOVERNMENT PRINTING OFFICE DID 0-366-35

1. A machine for blending various types of tobacco or like fibrousmaterials, comprising blending means; at least two conveyor lines forsupplying to said blending means different types of material; measuringmeans provided in one of said conveyor lines for determining the rate ofmaterial flow per unit of time therein and means provided in the otherconveyor line for regulating the rate of material flow as a function ofthe results of measurements carried out by said measuring means.
 2. Amachine as defined in claim 1, further comprising second material flowrate regulating means provided in said one conveyor line and includingsaid measuring means.
 3. A machine as defined in claim 1, wherein saidconveyor lines are arranged to supply the respective types of materialto said blending means at a constant ratio, said proportioning meanscomprising feeder means having a variable supply of the respectivematerial type for delivery to said blending means and means fordelivering to said feeder means material at a rate which is a functionof the quantity of material in said supply.
 4. A machine as defined inclaiM 1, wherein each of said conveyor lines comprises a conveyor forthe respective material type, variable-speed drive means for each ofsaid conveyors, and regulator means for regulating one of said drivemeans as a function of the speed of the other drive means.
 5. A machineas defined in claim 4, further comprising at least one processingapparatus provided in said one conveyor line intermediate sad ring meansand the respective conveyor for subjecting the respective material typeto at least one treatment for affecting the rate of delivery of materialper unit of time toward said measuring means, the conveyor in said oneconveyor line being arranged to supply to said processing apparatusmaterial at a rate which at least temporarily exceeds the capacity ofsaid processing apparatus whereby the processing apparatus refuses thesurplus of the thus delivered material, recirculating means forcollecting upstream of said processing apparatus such surplus materialwhich is refused by said processing apparatus, nd speed changer meansfor regulating the drive means of the conveyor in said one conveyor linea s a function of the amounts of refused material on said recirculatingmeans.
 6. A machine for blending various types of tobacco or likefibrous materials, comprising blending means; at least two conveyorlines for supplying to said blending means different types of material ameasuring device provided in one of said conveyor lines for determiningthe rate of material flow per unit of time; a proportioning deviceprovided in the other conveyor line for regulating the rate of materialflow as a function of the results of measurements carried out by saidmeasuring device; and timelag means provided in at least one of saidconveyor lines between said blending means and the respective device forregulating the time required by successive increments of the respectivematerial to cover the distance between the respective device and saidblending means.
 7. A machine as defined in claim 6 further comprising atleast one additional conveyor line for supplying to said blending meansa further type of material, one of said conveyor lines being arranged todeliver one type of said material at a speed which is less than thespeed of material in the remaining conveyor lines, one of said timelagmeans being provided in each of said remaining conveyor lines.
 8. Amachine for blending various types of tobacco or like fibrous materials,comprising blending means; at least two conveyor lines for supplying tosaid blending means different types of material, at least one adjustableprocessing apparatus provided in at least one of said conveyor lines andoperative to treat the respective material type; signal-generatingdetector means for detecting changes in the rate of supply of materialby one of said conveyor lines; and operating means for adjusting saidprocessing apparatus in response to signals from said detector means,said detector means and said processing apparatus being provided indifferent conveyor lines.
 9. A machine for blending various types totobacco or like fibrous materials, comprising blending means; at leasttwo conveyor lines for supplying to said blending means different typesof material; at least one first adjustable processing apparatus providedin at least one of said conveyor lines and operative to treat therespective material type; signal-generating detector means for detectingchanges in he rate of supply of material by one of said conveyor lines;first operating means for adjusting said processing apparatus inresponse to signals from said detector means; at least one secondadjustable processing apparatus provided in the other conveyor line andoperative to treat the respective material type; and second operatingmeans for adjusting said second processing apparatus in response tosignals received from said detector means, at least one of saidprocessing apparatus being arranged to add to a respective material typeone or more treating media and the rEspective operating means comprisingrated-value-setting means for selecting said treating media, saidrated-value-setting means having a plurality of settings in each ofwhich said rated-value-setting means selects a different treating mediumand said rated-value-setting means being adjustable to select at leastone new treating medium while said one processing apparatus treats acharge of material with a previously selected treating medium.
 10. Amachine for blending various types of tobacco or like fibrous materials,comprising blending means; at least two conveyor lines for supplying tosaid blending means different types of material; at least one firstadjustable processing apparatus provided in at least one of saidconveyor lines and operative to treat the respective material type;signal-generating detector means for detecting changes in the rate ofsupply of material by one of said conveyor lines; first operating meansfor adjusting said processing apparatus in response to signals from saiddetector means; at least one second adjustable processing apparatusprovided in the other conveyor line and operative to treat therespective material type; second operating means for adjusting saidsecond processing apparatus in response to signals from said detectormeans, at least one of said processing apparatus being arranged to addto a respective material type one or more treating media ad therespective operating means comprising rate-value-setting means forselecting said treating media; and locking means associated with saidrated-value-setting means to prevent changes in the addition of treatingmedia during treatment of a charge of the respective material type andto effect repeated addition of the same treating medium upon completionof the treatment of a charge.